JPH0644168B2 - Multicolor recorder - Google Patents

Description

The present invention relates to a multicolor recording apparatus for recording an image of two or more colors by forming an electrostatic latent image on a recording medium and developing the electrostatic latent image. Regarding

"Prior Art" An apparatus that forms an electrostatic latent image on a recording medium by using an electrophotographic method or an electrostatic recording method, develops the electrostatic latent image to obtain a toner image, and transfers the toner image to a recording sheet includes a copying apparatus. Are used in various recording devices. Various devices have been developed which use this apparatus to perform not only single color recording but also multicolor recording.

FIG. 3 shows a schematic configuration diagram showing one example thereof.

This multicolor recording apparatus has an exposure unit 2 on the outer periphery of a photosensitive drum 1.
The four developing devices 4a, 4b, 4c and 4d, the cleaning device 5, and the charging device 3 are provided.

Further, a transfer drum 6 is provided so as to circumscribe the photosensitive drum 1, and a recording paper 7 is wound around the outer periphery of the transfer drum 6. The exposure unit 2 is composed of an optical system for guiding an optical image to the outer peripheral surface of the photosensitive drum 1, or an optical writing head using an LED array or the like.
The developing devices 4a to 4d have cyan, magenta, and
This is a developing device that develops an electrostatic latent image by using toners of yellow color and black color.

In such a multi-color recording apparatus, when the photosensitive drum 1 rotates in the direction of the arrow, the outer peripheral surface of the photosensitive drum 1 is cleaned by the cleaning device, a constant charge is applied by the charger 3, and the electrostatic latent image is generated by the exposure unit 2. An image is formed.

Then, first, for example, an electrostatic latent image corresponding to cyan is formed, and a cyan toner image is formed by the developing device 4a. This toner image is transferred onto the recording paper 7 on the transfer drum 6. Next, the outer peripheral surface of the photosensitive drum 1 is cleaned again by the cleaning device 5, an appropriate electric charge is given by the charger 3, and an electrostatic latent image corresponding to magenta is formed in the exposure section 2 this time. This electrostatic latent image is developed by the developing device 4b and transferred again onto the recording paper 7. Similarly, when the yellow and black toner images are transferred onto the recording paper 7 in an overlapping manner, the recording of the multicolored recording image on the recording paper 7 is completed.

The transfer of each toner image is performed by the transfer drum 6 conveying the recording paper 7 and rotating the recording paper 7 so that the corresponding portions of the images overlap each other.

FIG. 4 shows an example of a multicolor recording apparatus having a structure different from that shown in FIG.

This device is provided with four photosensitive drums 1a to 1d on the conveyance path of the recording paper 7, and is configured to transfer a toner image onto the recording paper 7 by a transfer device 9, respectively.
An exposure unit 2, a charging device 3, a developing device 4, and a cleaning device 8 are provided on the outer circumference of each of the photosensitive drums 1a to 1d.

For example, in the photosensitive drum 1a, the electrostatic latent image formed by the exposure unit 2 is developed by the developing device 2 to form a cyan toner image. Then, this toner image is transferred to the recording paper 7 by the transfer device 9. Other photosensitive drum 1
The same applies to b, 1c, and 1d.

"Problems to be Solved by the Invention" However, the multicolor recording apparatus as shown in FIG. 3 has the advantage that the apparatus configuration is relatively compact, but the photosensitive drum 1 rotates once. Since one color is transferred each time, four colors are required to be transferred four times, which slows down the process speed.

On the other hand, in the multicolor recording apparatus shown in FIG. 4, although the improvement of the process speed has been solved, it is composed of four photosensitive drums, which causes an increase in the size of the apparatus or the recording paper 7 When carrying in order,
Due to the uneven transport speed, the toner images do not completely overlap with each other, causing a so-called color shift.

Further, in addition to the device described in FIGS. 3 and 4,
As an alternative to the photosensitive drum, an apparatus of a type has been developed in which an electrostatic recording head is used to irradiate ions on a recording medium made of an insulator to form an electrostatic latent image. To irradiate with such ions, for example, Japanese Patent Application Laid-Open No. 59-19
The electrostatic recording heads disclosed in JP-A-0854, JP-A-60-94357 and JP-A-60-89373 are used. This electrostatic recording head controls an ion flow generated by discharge using an electrode array in which a large number of electrodes are arranged, guides the ion flow onto a recording medium, and forms an electrostatic latent image by the ions. Is.

Even if such an electrostatic recording head is used, an apparatus having the same configuration can be realized, but there is a problem that is the same as that described above in terms of the process speed or the increase in size of the apparatus. there were.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and it is possible to provide a multi-color recording apparatus capable of high-speed printing, having a relatively compact structure, and having less color misregistration. It is intended.

"Means for Solving Problems" A multicolor recording apparatus according to a first aspect of the present invention includes a first recording medium drum and a first electrostatic recording head that forms an electrostatic latent image on an outer peripheral surface thereof. A first developing device for developing the electrostatic latent image to form a first toner image, a second recording medium drum, and second electrostatic recording for forming an electrostatic latent image on the outer peripheral surface thereof. It has a head and a second developing device for developing the electrostatic latent image to form a second toner image, and the first recording medium drum and the second recording medium drum are arranged circumscribed. The second above
An adhesive surface layer is provided on the outer peripheral surface of the recording medium drum, and the first recording medium drum has the first surface.
And a transfer means for transferring the first toner image transferred from the recording medium drum and the second toner image formed so as to be superposed on the first toner image onto the recording paper. is there.

The multicolor recording apparatus of the second invention develops the first recording medium drum, a first electrostatic recording head that forms an electrostatic latent image on the outer peripheral surface thereof, and the electrostatic latent image. A first developing device for forming a first toner image, a second recording medium drum arranged to transfer the first toner image from the first recording medium drum, and an outer peripheral surface thereof. A second electrostatic recording head that forms an electrostatic latent image, a second developing device that develops the electrostatic latent image to form a second toner image, the first recording medium drum to the first recording medium drum, Second toner image transferred onto the second recording medium drum and the second toner image formed on the first toner image
First transfer means for transferring the toner image of No. 2 onto a recording sheet, a third recording medium drum, a third electrostatic recording head for forming an electrostatic latent image on the outer peripheral surface thereof, A third developing device for developing the latent image to form a third toner image; and a fourth recording medium drum arranged to transfer the third toner image from the third recording medium drum. A fourth electrostatic recording head that forms an electrostatic latent image on its outer peripheral surface, a fourth developing device that develops the electrostatic latent image to form a fourth toner image, and the third recording. A second transfer unit for transferring the third toner image transferred from the medium drum to the fourth recording medium drum and the fourth toner image formed so as to be superposed on the third toner image onto a recording sheet. It is characterized by that.

An adhesive surface layer is preferably provided on the outer peripheral surfaces of the second recording medium drum and the fourth recording medium drum.

Further, it is preferable that the transfer means is a roll having a built-in heating element.

[Operation] As described above, in the present invention, each recording medium drum is provided with the electrostatic recording head and the developing device for forming a toner image for one color, and one recording medium drum to the other recording medium. After the toner image is transferred onto the drum, it is transferred onto the recording paper together with the toner image formed on the other recording medium drum, so that there is no risk of color misregistration or the like. Further, since the respective recording medium drums are arranged so as to be circumscribed with each other and the positional relationship between these drums is relatively flexible, the overall apparatus can be made compact. Here, if an adhesive surface layer is provided on the outer peripheral surface of the recording medium drum on the side to which the toner image is transferred, the toner image is satisfactorily transferred from one side to the other side. Then, when the toner image is transferred onto the recording paper, the transfer and the fixing can be performed at once by using a roll having a heating element as a transfer means.

[Embodiment] FIG. 1 is a schematic configuration diagram showing an embodiment of a multicolor recording apparatus of the present invention.

This apparatus includes two recording medium drums 1a which are circumscribed with each other.
And 1b, and a transfer means 9 circumscribing one recording medium drum 1b.

On the outer periphery of one recording medium drum 1a, an electrostatic recording head 2 that forms an electrostatic latent image thereon, a developing device 4a that develops the electrostatic latent image, a cleaning device 8, and two chargers 3 , 12 are arranged. Further, the electrostatic recording head 2 and the developing device 4b, the cleaning device 14, and the charging device 13 are arranged on the outer circumference of the other recording medium drum 1b.

The developing device 4a forms a toner image using, for example, red toner, and the developing device 4b forms a toner image using black toner. The chargers 3 and 13 are for adjusting the potential of the outer surface of the recording medium 1a or 1b before the electrostatic recording head 2 irradiates the recording medium 1a with ions. Further, the charger 12 is provided in order to remove electricity beforehand when the outer peripheral surface of the recording medium drum 1a is cleaned using the cleaning device 8.

The transfer unit 9 sandwiches the recording sheet 7 together with the recording medium drum 1b, and applies appropriate heat and pressure so that the toner image formed on the outer peripheral surface of the recording medium drum 1b is transferred to the recording sheet 7. It is provided.

The recording medium drum 1a has an outer peripheral surface coated with a film of aluminum oxide or the like, and the recording medium drum 1b has an outer peripheral surface provided with an adhesive insulator layer. The adhesive insulator layer is made of, for example, silicon rubber.

The multicolor recording apparatus of the present invention having the above configuration records a multicolor image on the recording paper 7 as follows.

First, the outer peripheral surface of the first recording medium drum 1a is neutralized by the charger 12, cleaned by the cleaning device 8, and given an appropriate potential by the charger 3. Next, the outer peripheral surface of the electrostatic recording head 2 is irradiated with ions to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 4a and a red toner image is formed.

The toner image is transferred from the first recording medium drum 1a to the second recording medium drum 1b at the circumscribing portion of the first recording medium drum 1a and the second recording medium drum 1b. In the case of this embodiment, the transfer of the toner image is due to the adhesive force of the adhesive insulator layer.

The potential of the outer peripheral surface of the second recording medium drum 1b is adjusted by the charging device 13, the electrostatic latent image is formed by the electrostatic recording head 2, and the black toner image is formed by the developing device 4b. This black toner image is formed on the red toner image already transferred to the outer peripheral surface of the second recording medium drum 1b. Then, the two toner images are simultaneously transferred onto the recording paper 7 by the transfer means 9. In this way, the two-color image is recorded on the recording paper 7.

FIG. 2 shows another embodiment of the present invention.

This multi-color recording device is exactly the same as the device shown in FIG.
Two sets of toner images of two colors are respectively transferred onto one sheet of recording paper 7 by a common transfer means 9 prepared as a set.

That is, with the first recording medium drum 1a and the second recording medium drum 1b, the same processing as in the apparatus of FIG.
Toner images corresponding to yellow and magenta are formed, and these toner images are transferred onto the recording paper 7 by the transfer means 9. On the other hand, a cyan toner image and a black toner image are formed by the recording medium drum 1c and the recording medium drum 1d, respectively, and these toner images are superposed and transferred onto the recording sheet 7 by the transfer means 9.

The electrostatic recording head 2, the developing device 4, the charging device 3, the cleaning device 8 and the like arranged on the outer circumference of each of the recording medium drums 1a to 1d have exactly the same functions as those described in FIG. I have. The recording medium drum 1b and the recording medium drum 1d each have an adhesive surface layer formed on the outer peripheral surface thereof. Further, in this embodiment, the toner images formed on the outer circumferences of the first recording medium drum 1a and the third recording medium drum 1c are the second recording medium drum 1b or the fourth recording medium drum, respectively. Immediately before being transferred to 1d, a charger 16 for adjusting the potential of the outer peripheral surface thereof is provided. The charger 16 adjusts the electric potential of the recording medium drum on the transfer side so that a constant electric potential difference is generated with respect to the electric potential of the recording medium drum on the transfer side, so that the transfer is surely and easily performed. If such a charger 16 is provided, the outer peripheral surface of the second recording medium drum 1b or the fourth recording medium drum 1d does not necessarily have to be adhesive, and the first recording medium drum 1a or the third recording medium drum 1d does not have to be adhesive. The outer peripheral surface may have the same structure as the recording medium drum 1c.

In addition, in the case of this embodiment, on the transfer means 9, the second
Although the position at which the toner image is transferred from the recording medium drum 1b of FIG. 4 and the position at which the toner image is transferred from the fourth recording medium drum 1d are slightly displaced, the transfer means has a drum shape as in the illustrated embodiment. If the recording paper 7 is in close contact with the transfer means 9, the possibility of color misregistration is extremely small. Further, if the transfer means is composed of a roll or the like having a built-in heating element, fixing can be performed simultaneously with transfer. In this way, the multicolor image of four colors can be recorded on the recording paper 7 by the apparatus of this embodiment.

"Modification" The multicolor recording apparatus of the present invention is not limited to the above embodiments.

The size, shape, arrangement, etc. of the recording medium drums may be freely changed as long as the toner images can be transferred to each other. Further, the number of charging devices, cleaning devices, etc. may be increased or decreased as necessary. Further, the transfer means may be replaced with various ones used in a known recording apparatus.

Further, although an example using the electrostatic recording head has been shown in the above-mentioned embodiment, for example, if a recording medium drum using a transparent silicon rubber as an adhesive surface layer or an ordinary photosensitive drum is used, an electrostatic electrostatic The present invention can also be implemented for a system that forms a latent image.

[Advantages of the Invention] According to the multicolor recording apparatus of the present invention described above, the recording paper is not repeatedly fed to the transfer portion, so that the recording speed can be increased, and the overall configuration of the apparatus is also compared. Can be compactly integrated. further,
There is very little risk of color misregistration at the transfer means. Further, the toner images of the respective colors can be freely overlapped with each other, and so-called secondary colors or more, which are obtained by mixing the toners, can be reproduced with sufficient density. Therefore, extremely high quality multicolor recording can be performed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a multicolor recording apparatus of the present invention, FIG. 2 is a schematic configuration diagram showing another embodiment thereof, and FIG. 3 is a schematic configuration showing an example of a conventional recording apparatus. FIG. 4 and FIG. 4 are schematic configuration diagrams showing another embodiment of another conventional recording apparatus. 1a, 1b, 1c, 1d ... Recording medium drum, 2 ... Electrostatic recording head, 3 ... Charging device, 4a, 4b, 4c, 4d ... Developing device, 7 ... Recording paper, 8 ... Cleaning device , 9 ... Transferring means.

Claims (4)

[Claims] 1. A first recording medium drum, a first electrostatic recording head for forming an electrostatic latent image on an outer peripheral surface thereof, and the electrostatic latent image is developed to form a first toner image. A first developing device, a second recording medium drum, a second electrostatic recording head that forms an electrostatic latent image on its outer peripheral surface, and the electrostatic latent image is developed to form a second toner image. A second developing device to be formed, the first recording medium drum and the second recording medium drum are arranged circumscribed, and an adhesive surface layer is provided on the outer peripheral surface of the second recording medium drum. Further, on the second recording medium drum, a recording sheet on which the first toner image transferred from the first recording medium drum and the second toner image formed so as to be superposed on the first toner image are recorded. A multicolor recording apparatus, characterized in that a transfer means for transferring the image onto the multicolor recording apparatus is provided. 2. A first recording medium drum, a first electrostatic recording head for forming an electrostatic latent image on an outer peripheral surface thereof, and the electrostatic latent image is developed to form a first toner image. A first developing device; a second recording medium drum arranged to transfer the first toner image from the first recording medium drum;
A second electrostatic recording head that forms an electrostatic latent image on its outer peripheral surface, a second developing device that develops the electrostatic latent image to form a second toner image, and the first recording medium. A first transfer unit configured to transfer, onto a recording sheet, the first toner image transferred from the drum to the second recording medium drum and the second toner image formed so as to be superposed on the first toner image; Recording medium drum, a third electrostatic recording head that forms an electrostatic latent image on the outer peripheral surface thereof, and a third developing device that develops the electrostatic latent image to form a third toner image. A fourth recording medium drum arranged so that the third toner image is transferred from the third recording medium drum, and a fourth electrostatic latent image is formed on the outer peripheral surface thereof.
Of the electrostatic recording head, a fourth developing device for developing the electrostatic latent image to form a fourth toner image, and the third recording medium drum to the fourth recording medium drum. Third
2. A multicolor recording apparatus comprising: a second transfer unit configured to transfer the toner image and the fourth toner image formed on the toner image onto a recording sheet. 3. An adhesive surface layer is provided on outer peripheral surfaces of the second recording medium drum and the fourth recording medium drum, and the multi-layer recording medium according to claim 2, Color recording device. 4. The multicolor recording apparatus according to claim 2, wherein said transfer means comprises a roll containing a heating element.